This process relates generally to a process for recovering metals from metal-bearing materials, and more specifically, a process for recovering copper and other metals through high temperature pressure leaching in a pressure leaching vessel wherein a seeding agent is added to the pressure leaching vessel during the oxidation process.
The recovery of copper from copper sulfide concentrates using pressure leaching has proven to be a potentially economically attractive alternative to smelting. Pressure leaching operations generally produce less fugitive emissions than smelting operations, and thus, environmental benefits may be realized. Further, pressure leaching circuits may be more cost-effectively constructed on-site at a concentrator, eliminating the expense associated with concentrate transportation that smelting operations may require. Further, any by-product acid produced in the pressure leaching circuit may be used in adjacent heap leaching operations, thus offsetting the costs associated with purchased acid.
On the other hand, the application of pressure leaching may result in unacceptably high copper and precious metal losses. A significant cause of such metal losses has been identified when metal values become occluded by materials present in the pressure leaching vessel, such as, for example, hematite and/or other materials, rendering these metal values unavailable to subsequent processing, which results in these metal values being lost.
An effective and efficient method to recover copper from copper-containing materials, especially copper from copper sulfides such as chalcopyrite and chalcocite, that enables high copper recovery to be achieved at a reduced cost over conventional processing techniques and that enhances the recovery of precious metals from metal-bearing materials would be advantageous.